1. Field of the Invention
The present invention relates to a printing device and, in particular, to a printing device for printing a strip-like printing article (i.e., an article to be printed) of the type in which printing is intermittently performed on the printing article by a printing impression roller which moves forwards in a direction perpendicular to a direction of feeding the strip-like printing article while rotating in one direction and moves backwards while rotating in the opposite direction. The present invention also relates to a die-cutting device which die-cuts or punches into a desired shape a strip-like printed article printed by a printing device as described above.
2. Description of Related Art
A printing device of the above-described type has been known, e.g., from U.S. Pat. No. 4,057,013 and U.S. Pat. No. 4,691,630. Although low in printing speed, the printing device of this type is simple in construction, relatively small in size and is suitable for multicolor printing of a small number of printing articles such as labels. Further, since the strip-like printing article is kept flat and is not subjected to bending during the printing process, it has been utilized for printing a printing article such as a label, as shown in FIG. 2, which has a construction made up of relatively thick multiple layers having an adhesive agent layer.
A conventional printing device of this type has the following construction as schematically shown in FIG. 25. Namely, a printing block 56a having a plurality of printing stamps for printing a plurality of different colors is fixed to a single printing impression roller (or a printing roller) 38a. The strip-like printing article S1a is moved by intermittently feeding by a distance corresponding to each printing stamp. While the feeding is temporarily stopped, the printing impression roller 38a is moved forwards or backwards in a direction perpendicular to the direction of feeding the strip-like printing article S1a, thereby printing the strip-like printing article S1a. On the printing portion on a single frame of the printing article S1a, there are sequentially printed a plurality of colors by means of the plurality of printing stamps which are provided on the printing block 56a. It is thus so arranged that the multicolor printing in each frame is completed when the printing article S1a has passed through the area in which the printing impression roller 38a moves forwards and backwards.
In this conventional printing device, in order to apply inks from upper ink tanks 12a to the printing impression roller 38a, there is provided in a stationary positional relationship a roller train 48a which is made up, as shown in FIGS. 26A through 26C, of a metallic ink fountain roller (or bottling roller) 13a which feeds inks from the ink tanks 12a, a rubber duct roller (or access roller) 15a which rotates in contact with the periphery of the ink fountain roller 13a, and a group of ink distribution rollers (or ink kneading rollers) 47a which are disposed between the duct roller 15a and two metallic ink rollers (or inking rollers) 16a, 17a and which are made up of a plurality of rubber rollers 45a and metallic rollers 46a whose peripheries are held in consecutive contact with each other. In order to supply inks to the two ink rollers 16a, 17a, the roller train 48a is divided into two on the way to the ink rollers 16a, 17a. If necessary, there are also provided rollers 49a, 49a, in a stationary relationship, between the two ink rollers 16a, 17a, as shown in FIGS. 26A and 26C, in order to equalize the amounts of inks. In this roller train 48a, the ink fountain roller 13a is driven by an electric motor. The duct roller 15a is swung into alternate contact with the ink fountain roller 13a and one of the group of the ink distribution rollers 47a so as to transfer the inks. The metallic rollers 46a among the group of the ink distribution rollers 47a and the two ink rollers 16a, 17a are driven by electric motors, and the rubber rollers 45a are rotated by coming into frictional contact with these motor-driven rollers. On the peripheral surface of each of the ink rollers 16a, 17a a rubber form roller (or an ink application roller of rubber make) 41a is respectively rotated through frictional contact therewith. Each of the form rollers 41a is mounted on a swinging arm whose operation is controlled by a cam mechanism. By the swinging movement of the form rollers 41a, the bottom portions of the form rollers 41a are brought into intermittent contact with the printing impression roller 38a which moves forwards and backwards under the ink rollers 16a, 17a in the direction of an arrow X in FIG. 25. The inks are thus applied from the ink rollers 16a, 17a to the printing blocks 56a of the printing impression roller 38a. For example, in the conventional example shown in FIG. 26A, the printing impression roller 38a advances while rotating from the right side or the left side which is perpendicular to the direction of feeding of the strip-like printing article S1a which is fed, on a flat printing pressuring base 36a, in a direction perpendicular to the surface of the figure sheet, thereby printing on the printing surface of the strip-like printing article S1a. Before the printing impression roller 38a reaches the printing article S1a, the form rollers 41a are kept waiting by swinging forwards in the travelling directions. The printing impression roller 38a pushes the form rollers 41a while pushing them upwards through rotational contact therewith. At the time of their contact, the inks on the peripheries of the form rollers 41a are applied or coated to the printing block 56a of the printing impression roller 38a. The rollers of the roller train 48a are provided to coat the inks to be supplied from the ink tanks 12a to the ink rollers 16a, 17a to a uniform thickness. While the inks are transmitted through respective rollers which are in rotational contacts with each other, unevenness of the ink distribution disappears.
In case printing of three colors is performed on the strip-like printing article S1a, a printing block 56a having three kinds of stamps, for example, is mounted on the printing impression roller 38a as shown in FIG. 25. The ink tanks 12a which are divided so as to be able to contain therein three colors of inks are also prepared. The inks to be fed from the ink tanks 12a are transmitted in the form of stripes or bands of three colors as divided in the longitudinal or axial direction of each roller. The ink rollers 16a, 17a are thus uniformly coated with each color of inks. These three colors of inks are respectively coated on the three stamps of the printing block 56a by means of the form rollers 41a. In the example shown in FIG. 25, since the stamps of the printing block 56a are three in number, there will be carried out a simultaneous printing of three frames each time the printing impression roller 38a rolls on the printing article S1a. Whenever one step or one time of printing work has been finished, the strip-like printing article S1a is intermittently fed by a suitable intermittent feeding means by a distance which is equivalent to the length of one frame and a distance between the frames. When three times of intermittent feeding have been finished, one unit of the printing process will be finished.
In case a label of released adhesion type is manufactured, there is used a strip-like printing article S1a, as shown in FIG. 2, in which a released paper is multiplied (or added) via an adhesive (mainly pressure sensitive adhesive) agent layer, on the rear surface of a printing paper. After the above-described printing process has been finished, a transparent adhesive film, for example, is laminated on the printed surface. The transparent adhesive film, the printing paper and the adhesive agent layer except for the released paper are die-cut (or cut by die-cutting) along the above-described frame. An unnecessary portion of the printing paper is released from the released paper together with the adhesive agent layer and the transparent adhesive film, thereby obtaining labels provided with a released paper. The die-cutting device for performing this die-cutting work has a construction as shown in FIGS. 27 and 28. Namely, a lower chase plate 129a is mounted on a substantially horizontal upper surface of a stationary lower frame 103a. To a lower surface of an upper frame 102a which is screwed to four supporting columns 107a which can move up and down through a vertical movement mechanism of a crank or the like, there is fixed an upper chase plate 105a which is made of a thick steel plate and is provided on its lower surface with a punching or die-cutting blade 104a. The upper chase plate 105a is arranged to be movable towards and away from the upper surface of the lower chase plate 129a. The strip-like printed article S2a which has been printed is intermittently fed to a space between the upper chase plate 105a and the lower chase plate 129a with the printed surface looking upwards. While the feeding is stopped, the upper frame 102a is lowered so that the punching blade 104a of the upper chase plate 105a comes into cutting engagement with the surface of the strip-like printed article S2a, thereby die-cutting it except the released paper. The punching blade 104a is made by continuously arranging a thin blade into a square, a circle or the like shape corresponding to the shape of the outline of the printing frame. When the outline of the printing frame has been changed in shape, the shape of the punching blade is also changed.
In order to enable the adjustment of the punching blade 104a, the upper chase plate 105a is mounted so as to be movable back and forth along a pair of guide rails 108a of substantially L-shape in cross section which are provided on both sides of a rotatable plate 109a which is rotatable by a rotation-adjustment bolt 110a relative to the upper frame 102a. After rotation adjustment, it is immovably fixed by a suitable fixing means. In case the shape of the punching blade 104a is changed, the upper chase plate 105a is pulled out of the rails 108a of the rotatable plate 109a and then a replacement work of the punching blade is performed. The punching blade 104a is normally fixed to the upper chase plate 105a with a pressure sensitive adhesive double coated tape.
In case printing of different colors or pattern is to be made on another strip-like printing article S1a after having finished the printing on one strip-like printing article S1a, the following procedure must be followed. Namely, the printing block 56a on the printing impression roller 38a is replaced. The ink tanks 12a, the rollers of the roller train 48a, the ink rollers 16a, 17a and the form rollers 41a are cleaned by letting a cleaning liquid flow from the ink tanks 12a downwards into a pan which is prepared below the form rollers 41a. Then, the ink tanks 12a are filled with new inks and the inks are distributed or kneaded by rotating all the rollers between the ink tanks 12a and the form rollers 41a until the inks are uniformly coated on the ink rollers 16, 17. When a condition in which the form rollers 41a have no more uneven distribution of the inks has been attained, the printing work is started. In the conventional printing device, the number of rollers which are present between the ink tanks 12a and the ink rollers 16a, 17a, i.e., those which constitute the roller train 48a is large. Therefore, it takes long time before the inks reach the ink rollers 16a, 17a and there was a disadvantage in that the time of distributing the inks becomes long. In order to shorten this time, the speed of rotation of the rollers may be increased. However, the inks may splash from many points of contacts among rollers, with the result that the printing device is stained inside, giving rise to a possibility of staining the printing article S1a. In addition, the rollers may be heated through an increase in the number of frictional rotation, which may give rise to a cause of mechanical troubles or change (or deterioration) in color of the inks, which is of course to be avoided.
As described above, in these rollers there are used rubber rollers and metallic rollers. In FIGS. 26A through 26C, the hatched rollers are of rubber make and the remaining rollers are of metallic make. Each of the rubber rollers is provided with dented grooves 49a as shown in FIG. 29. For example, in the case of the ink fountain roller 15a for three colors, the roller is divided, as shown therein, into three sections as divided in the longitudinal or axial direction with a groove 49a in between so that the inks of different colors to be adhered to the three surfaces do not get mixed. The metallic rollers have no such grooves because they have smoother surfaces than those of the rubber rollers and consequently the inks have no tendency of spreading sidewise. In case the number of colors is changed from three to four, the rubber rollers must be changed to those whose surfaces are divided into four sections. However, the stationary roller arrangement like in FIGS. 26A through 26C has a large number of rollers and is time consuming in their replacement. During this replacement work, the printing device cannot be operated and the printing device is therefore poor in operating efficiency. When the number of colors has been changed, the same kind of cleaning work as has been explained hereinabove is made before the replacement work in order to clean the metallic rollers such as the ink rollers 16a, 17a that have not been replaced. Thereafter, predetermined inks are prepared in the ink tanks 12a and these rollers are rotated to distribute the inks. The printing work will be started after the inks have been distributed.
In case the strip-like printing article S1a is in the form of labels and their printing dimensions and shape have been changed, the punching blade 104a for die-cutting is also replaced accordingly by taking it out of the rails 108a together with the upper chase plate 105a. The punching blade 104a must also be pulled out when checking thereof must be done during the die-cutting work. However, since the upper chase plate 105a is made of a metal and is therefore very heavy, there is a possibility of inadvertently dropping it out of position or onto the floor when the upper chase plate 105a is pulled out.
In view of the foregoing disadvantages of the conventional printing device, the present invention has an object of providing a printing device of the type in which the printing impression roller moves forwards and backwards in a direction perpendicular to a direction of feeding a strip-like printing article, which printing device having an improved operating efficiency in that the replacement of the printing rollers can be made in a shorter time and that the cleaning of the rollers and the distribution of the inks can also be made in a shorter time, with a smaller amount of splashing of the inks. Another object of the present invention is to provide a printing device which is cheap in the cost of replacing the rollers and in the running cost. It is still another object of the present invention to provide a die-cutting device for die-cutting the strip-like printed article which has been printed by such a printing device as described above, which die-cutting device being of vertically movable type in which the punching blade to die-cut the printed strip-like printed article can be replaced or inspected safely and easily.